The growth of the cable TV industry and the satellite broadcast industry has provided consumers with a veritable cornucopia of content for their viewing pleasure. With the current offerings of some cable and satellite broadcasters, it is not uncommon for a household to have access to as many as 200 channels. With such an entertainment bonanza at stake, it is no surprise that people who pirate cable and satellite signals abound.
Generally, the conditional access system that is used to prevent access to the cable and satellite signals is hardware based. The signal from the service provider is transmitted or broadcast to all users in an encrypted format or a scrambled format and only those users who have the proper facilities and access codes can decrypt or descramble the signals. The access codes are currently stored in smart cards that have to be inserted in the set top boxes (STB) that are used as cable and/or satellite boxes. Unfortunately, that smart cards are very vulnerable to cloning and/or copying such that a cloned card, used on a proper STB, can give an end user practically complete access to all the offerings of the cable/satellite feeds without paying for them.
It should be noted that current smart cards are used to store data that is used to decrypt a control word from the service provider's server. The decrypted control word is then passed to a descrambler that descrambles the content stream received from the server.
One of the main vulnerabilities of the smart cards lies in their static physicality. The cards are removable, easily cloned, and, as such, the cloned cards are easily distributable to the ever willing consumer who wants something for almost nothing. The sheer physicality of the card is one feature that militates against frequent card and/or code changes. To change the cards, the content distributors (the cable and satellite companies) must send out new cards to their subscribers and must therefore bear the costs of such a large distribution. To attempt changing the code with any frequency that hampers these content stream pirates is to bear the brunt of massive distribution and/or retooling costs. A few companies have announced that smart cards and the codes on them will be changed once a year. However, such a low replacement frequency will still give pirates a chance to formulate either a workaround to the new cards or a chance to clone and distribute the new cards.
What is therefore required is a solution which avoids or at least mitigates the shortcomings of the prior art. Such a solution should allow service providers to change control words or access codes or keys without the large expenses attendant with the use of smart cards of other hardware based solutions. Ideally, such a solution should also allow service providers to update whatever encoding schemes are being used with minimal effort and expense.